- New Japanese encephalitis vaccine indicated for children and adults -

- About 3 billion people living in Asia Pacific are at risk of Japanese encephalitis -

Sanofi Pasteur, the vaccines division of Sanofi (EURONEXT: SAN and NYSE: SNY), announced today that its next generation vaccine against Japanese encephalitis (JE) is now available in Thailand. The innovative JE vaccine requires a single dose for immunization against JE in adults. In children, a booster dose is recommended 12 to 24 months after the primary injection to ensure long-term protection.

About 3 billion people in the Asia Pacific Region are at risk of JE[1] for which there is no specific treatment[2]. JE is most common in children under 15 years of age. It is the leading cause of childhood viral neurological infection and disability in Asia. 20-30% of JE affected people die. 50% of survivors are left with long-term sequelae[3]. In Thailand JE vaccination was introduced in the 1990's along with vector control and educational programs. As a result, the incidence of JE was greatly reduced. Yet, the JE virus remains the cause of 15% of viral encephalitis in Thailand[4].

"There is no specific treatment for Japanese encephalitisand vaccination is the most effective way to be protected," said Kulkanya Chokephaibulkit, Professor of Pediatric Infectious Diseases at Siriraj Medical School. "This new Japanese encephalitisvaccinehas shown to provide seroprotection to 96%of thechildren just 1 month after one doseand long term protection after a booster[5].Itshould stimulategreateradoptionofvaccinationagainst Japanese encephalitisinThailandin order tomoreefficientlyprotect children and adults against thisdevastatingdisease."

The Thai health authorities granted marketing authorization to the new JE Vaccine vaccine based on the review of clinical studies involving over 4,000 children and adults which demonstrated the safety of the vaccine and its ability to generate a protective immune response with one dose.

"Thisis an innovative vaccine that confers high-levelprotection against Japanese encephalitis after one dose. It can be easily integrated in the pediatric immunization schedule," said Emin Turan, General Manager Sanofi Pasteur in Thailand. "We believethe new Japanese encephalitisvaccinewill help reduce the burden of this devastating disease in children and contribute to improve public health inThailand."

About Sanofi Pasteur new JE vaccine

Sanofi Pasteur JE vaccine is a live-attenuated vaccine indicated for active immunization of people 12 months and older. The clinical data supporting the use of Sanofi Pasteur JE vaccine in children and in adults have been generated in multi-center studies conducted in the United-States, Australia, Thailand, and the Philippines with more than 2,400 adults and 2,200 children receiving Sanofi Pasteur JE vaccine. The safety and immunogenicity of the vaccine were compared to a licensed JE vaccine and placebo in adults and to a control vaccine in children. A pivotal Phase III study in adults showed that a single dose of Sanofi Pasteur JE vaccine is as immunogenic as three doses of the control vaccine. A single administration of Sanofi Pasteur JE vaccine elicited a protective level of neutralizing antibodies in approximately 93% and 99% of adults 14 days and 28 days after vaccine administration, respectively[5]. Over 84% of adults were still seroprotected 5 years after vaccination[6]. A Phase III study in children showed that approximately 95% of JE virus naive subjects were seroprotected 28 days after a single dose of Sanofi Pasteur JE vaccine[7]. The vaccine was well tolerated and there was no indication during the clinical development program of any safety concerns. The frequency of local and systemic reactions was comparable to those reported after administration of a placebo or a control vaccine.

About Japanese encephalitis

JE is caused by a virus transmitted by mosquitoes. The disease is neuro invasive with inflammation of the brain and its membranes (meninges). Most JE virus infections are mild (fever and headache) or without apparent symptoms, but up to 1 to 200 infections results in severe disease characterized by rapid onset of high fever, headache, neck stiffness, disorientation, coma, seizures, spastic paralysis and death. The case fatality rate is 30-35% among those with disease symptoms with over 15,000 deaths per year[8]; 50% of those who survive suffer from lasting damage to the central nervous system. In areas where the JE virus is common, encephalitis occurs mainly in young children[9].

About Sanofi

Sanofi, a global and diversified healthcare leader, discovers, develops and distributes therapeutic solutions focused on patients' needs. Sanofi has core strengths in the field of healthcare with seven growth platforms: diabetes solutions, human vaccines, innovative drugs, consumer healthcare, emerging markets, animal health and the new Genzyme. Sanofi is listed in Paris (EURONEXT: SAN) and in New York (NYSE: SNY).

Sanofi Pasteur, the vaccines division of Sanofi, provides more than 1 billion doses of vaccine each year, making it possible to immunize more than 500 million people across the globe. A world leader in the vaccine industry, Sanofi Pasteur offers the broadest range of vaccines protecting against 20 infectious diseases. The company's heritage, to create vaccines that protect life, dates back more than a century. Sanofi Pasteur is the largest company entirely dedicated to vaccines. Every day, the company invests more than EUR 1 million in research and development. For more information, please visit: http://www.sanofipasteur.com or http://www.sanofipasteur.us

9. United Nations The United Nations urbanization prospects: the 2005 revision. POP/DB/WUP/Rev.2005/1/F1. New York: United Nations; 2005

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